Mountain bicycle frame



FIG. 1 is a front elevational view of a mountain bicycle frame showingmy new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a side elevational view thereof from the left of FIG. 2;

FIG. 4 is a side elevational view thereof from the right of FIG. 2;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a top, front, and side perspective view thereof from the leftof FIG. 2;

FIG. 7 is a top, rear, and side perspective view thereof from the leftof FIG. 2; and,

FIG. 8 is a bottom plan view thereof.

The ornamental design for a mountain bicycle frame, as shown.